Quoted from 4Max:
Well first markg thank you for your answer (again) and secondly maybe saving me hours (months) of pain! Your theory is fascinating... and that Gottlieb assumes pinball players would struggle with arithmetic that was target - 1 . Thank you as always.
I'm sure Gottlieb got complaints. When I had my pinball arcade, two college guys figured out how to make my Gottlieb "300" match.